Ana kera bututun ƙarfe masu zafi ta hanyar wucewar ƙarfen madauri ta hanyar rollers don cimma takamaiman girman jiki.Samfurin da aka gama yana da ƙaƙƙarfan ƙarewa tare da sasanninta radiused, kuma ko dai wani welded ko gini mara kyau.Har ila yau ana amfani da bututu mai karfin wuta a tsarin tsarin hawan hasken rana, ginin gini.
Kera zafi mai birgima murabba'in karfe tubing ya haɗa da mirgina karfe a yanayin zafi sama da 1,000